It is well known that macroscopic aggregates or bundles of asbestos, especially of the chrysotile variety, can be converted into a stable dispersion or colloidal form by treatment with an aqueous solution of organic detergent surface active agent. Suitable types of surfactants for this procedure are described in U.S. Pat. No. 2,626,213.
It is also known that diluted asbestos dispersions may be converted into solid form by bringing a sheet, strand or other body of the dispersion into contact with an agent that renders the soap insoluble. In most commercial processes, the dispersion is passed through a nozzle or other forming channel and is brought into contact with an aqueous bath containing divalent or trivalent metal ions, such as calcium, magnesium, aluminum or the like. The metal ions react with the surfactant and cause the dispersion to be converted into a solid strand. The strand may be produced continuously and may be collected in a package such as by pot spinning. The package is then dried, cleaned to remove the insoluble soap residue, and then may be woven into a fabric or utilized in other applications. Typical processes are described in the following U.S. Pat. Nos. 2,972,221; 3,475,894; 3,608,294; 3,676,038; 3,634,568; and 3,806,572.
After the sheet or strand has been subjected to the precipitating agent, and up to the time of cleaning, several intervening operations take place that may result in the generation of waste. For example, the strand may break during the collection, winding, twisting, weaving or beaming operations, resulting in losses of asbestos mineral fibers which heretofore had to be disposed of in according with hazardous materials disposal regulations.
Such waste asbestos containing the insoluble soap, resulted in a direct loss to production efficiency and a gain in product cost. Also, since asbestos dust is considered dangerous to human health, proper disposal of the waste over a period of time can present serious difficulties to the producer.
According, the provision of a suitable and reliable method of converting such asbestos waste into a form suitable for reprocessing is highly desirable.